Considering they deal with elopement, opium dens, and even murderers, Sherlock Holmes tales are pretty darn pure – at least, in sexual terms. Not only is the Great Detective himself practically asexual, but his intellectual friendship with Watson comes at the expense of Watson's own romantic forays: practically every story begins with Watson ditching his wife, Mary, and running off to hang out with his best buddy Holmes instead.
While there have been theories for years that there's a little sumthin'-sumthin' going on between Watson and Holmes, you could argue that it almost doesn't matter if there is. The emphasis in these stories – and in Holmes and Watson's own friendship – is on intellectual reasoning and not on personal desire. Of course, we do have to note that, even if the Great Detective himself seems to be sexless, Holmes's clients get up to all kinds of romance-inspired hijinks on their own – there's the elopement of Hatty Doran in "The Noble Bachelor," for example. But even in these instances, there's no explicit sexual content to make your grandmother or your kid siblings blush.